The aim of this study was to determine the incidence of cysts and cystoid-solid lesions in thyroid carcinomas basing on preoperative ultrasonographic examinations (USG), fine needle aspiration biopsy (FNAB) and postoperative histopathological examinations. 661 patients with different thyroid disorders were treated surgically. Carcinoma was found in 46 patients (3.9%). Papillary carcinoma was predominant (n = 34). Of the 46 patients with carcinoma, preoperative USG examination revealed cystic or cystoid-solid lesions in 18 patients (39%). FNAB of this 18 patients was positive in 5 cases, negative in 4 and suspect in 9. In 6 cases the neoplastic lesion was strictly connected with cysts (foci in the wall or in solid masses within the cyst) and in the remaining 12 patients lesions were found in the vicinity of the neoplastic focus. We conclude that malignant neoplasms of the thyroid gland are frequently (in approximately 40%) accompanied by cystic and cystoid-solid lesions, FNAB diagnostic material should be obtained even through several USG-controlled punctures and negative FNAB does not exclude thyroid carcinoma, particularly in nodular-cystoid goitre.